The use of ophthalmic lenses for the correction of ametropia is well known. For example, multifocal lenses, such as progressive addition lenses (“PALs”), are used for the treatment of presbyopia. Typically, the progressive surface of a PAL has three zones, one zone each of far, intermediate, and near vision power. This refractive power is provided in a gradual, continuous progression of vertically increasing dioptric power from far to near focus, or top to bottom of the lens.
One disadvantage of the conventional progressive lens is that the inferior-most portion of the lens contains the add power, or near vision correction power. This placement of the add power is convenient when the lens wearer is reading. However, the lens wearer frequently performs tasks requiring the viewing of objects through the lower portion of the lens, which objects are outside of the near vision range, making this placement problematic. For example, when a PAL wearer walks down a staircase, the image of the stairs appears blurred and rounded when the lens wearer looks through the inferior-most region of the lens. The reason for this is that the stairs are more than 45 cm from the wearer's eye and the wearer is looking through the near vision zone of the lens, which zone cannot provide the refractive power for clear visualization of the stairs. Therefore, a need exists for a progressive addition lens in which this disadvantage is overcome.